Strategies to increase rice productivity to meet the global demand have been the main concern of breeders around the world. Although a growing number of functional genes related to crop yield have been characterized, our understanding of its associated regulatory pathways is limited. Using rice as a model, we find that blocking miR396 greatly increases grain yield by modulating development of auxiliary branches and spikelets through direct induction of the growth regulating factor 6 (OsGRF6) gene. The upregulation of OsGRF6 results in the coordinated activation of several immediate downstream biological clades, including auxin (IAA) biosynthesis, auxin response factors, and branch and spikelet development-related transcription factors. This study describes a conserved microRNA (miRNA)-dependent regulatory module that integrates inflorescence development, auxin biosynthesis and signalling pathways, and could potentially be used in engineering high-yield crop plants.

In this paper, we prove that a stochastic logistic population under regime switching controlled by a Markov chain is either stochastically permanent or extinctive, and we obtain the sufficient and necessary conditions for stochastic permanence and extinction under some assumptions. In the case of stochastic permanence we estimate the limit of the average in time of the sample path of the solution by two constants related to the stationary probability distribution of the Markov chain and the parameters of the subsystems of the population model. Finally, we illustrate our conclusions through two examples

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This paper discusses a randomized nonautonomous logistic equationwhere B(t) is 1-dimensional standard Brownian motion. We show that E[1/N(t)] has a unique positive T -periodic solution E[1/N p (t)] provided a(t), b(t), and α(t) are continuous T -periodic functions, a(t) > 0, b(t) > 0 and T 0 [a(s) − α 2 (s)] ds > 0.  2004 Elsevier Inc. All rights reserved.

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An improved technique has been developed for the successful fabrication of reticulate porous ceramics (RPCs) with strong struts, using polyurethane sponge as the template. In this technique, the coating process is composed of two stages. In the first stage, a thicker slurry is used to coat the sponge substrate uniformly. The green body is preheated to produce a reticulated preform with sufficient handling strength after the sponge has been burned out. In the second stage, a thinner slurry is used to coat the preform repeatedly, so that that struts are greatly thickened. Furthermore, large flaws, such as longitudinal strut cracks, are eliminated by the recoating process. The mechanical properties of RPCs should be improved significantly by this technique, which will make this material conducive for use in new technological applications.